反应详情

Methyl trans-4-[{2-[(t-butoxycarbonyl)amino]ethyl}-(chloroacetyl)amino]cyclohexanecarboxylate (560 mg) obtained in Reference Example 71(2) is dissolved in N,N-dimethylacetamide (5 ml), and 60% sodium hydride in oil (119 mg) is added thereto under ice-cooling. The reaction solution is then stirred for 0.5 hours under the same cooling conditions. Saturated aqueous ammonium chloride solution and water are poured to the reaction solution successively under ice-cooling, and the mixture is extracted with ethyl acetate. The organic layer is washed with water and saturated brine successively, dried over sodium sulfate and evaporated to remove the solvent under reduced pressure. The resulting residue is purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=1/1) to give t-butyl 4-[trans-4-(methoxycarbonyl)cyclohexyl]-3-oxopiperazine-1-carboxylate (302 mg).

1. temperatureunder ice-cooling
2. temperaturesame cooling conditions
3. temperaturecooling
4. extractionthe mixture is extracted with ethyl acetate
5. washThe organic layer is washed with water and saturated brine successively
6. dry with materialdried over sodium sulfate
7. customevaporated
8. customto remove the solvent under reduced pressure
9. customThe resulting residue is purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=1/1)